Reversing mechanism for type impression machines



June 20, 1933. P. P. BOURQUIN REVERSING MECHANISM FOR TYPE IMPRESSION MACHINES Filed Nov. 19, 1950 ryam W m m Patented June 26, 1.933

E TATES PATENT CECE PAUL PIERRE BOURQUIN, OF PHILADELPHIA, PENNSYLVANIA Application filed November 19, 1930. Serial No. 486,607.

My invention relates to ribbon reversing mechanism for type impression machines, such as typewriters and calculating machines, shorthand machines, etc.

Its primary object is to furnish a simple and efficient mechanism for causing the ribbon to change its direction of travel at the will of the operator.

A further object is to have all the working parts easily accessible for the purpose of lubricating and for cleaning.

A further object is to set the ribbon reversing mechanism in an inoperative position when it is desired to replace a worn ribbon with a new one.

Further purposes will appear in the specification and in the claims.

I have preferred to illustrate my invention in one main form only, selecting a form that is practical and efficient in operation and which Well illustrates the principles involved.

Figure 1 is a plan view of my improved ribbon reversing mechanism. Figure 2 is a side elevation thereof.

Figure 3 is a detached view of one element, illustrating its two engaging positions.

Figure 4 is a sectional view on the line 44 of Figure 1, illustrating the path of the ribbon.

Like numerals'refer to like parts in all figures.

Describing in illustration and not in limitation and referring to the drawing is a cylindrical platen adapted to be moved in the direction of the arrow A by any suitable mechanism, such as, for example, that illustrated in my copending application entitled Paper feed for shorthand typewriters, Serial No. 365,291, filed May 23, 1929. Y

My invention is not concerned with the details of the machine upon which it is used, such as the keyboard, striking mechanism, shift mechanism (if it be applied to a type writer), and therefore I do not illustrate or describe any such nonessential features.

A shaft 11 supported in the side frames 12 of the machine, carries the platen 10.

Fixed to one end, and turning therewith, is a bevel gear 13. This gear meshes with a second bevel gear 14 supported on a shaft 15, and carried at right angles to and in line with the shaft 11 by a suitable yoke support 16. I

The yoke support has four depending ears 17, 18, 19 and 20. The ear 17, surrounding the platen shaft 11, acts as a support for one side of the yoke itself, while the ears 18 and 19 at the ends thereof support the shaft and therewith the bevel gear 14, and the car 20 forms a support for the yoke member 16 at the side opposite the ear 17 Each outward end of the shaft 15 is provided with a worm 21 or 22 which meshes with a worm wheel 23 or 24, respectively mounted on a shaft 25 or 26.

The two shafts 25 and 26 have wound upon them, in the manner shown in Figure 4, the free ends of a ribbon 27, one end being fastened to the shaft 25 and the other end to the shaft 26. This ribbon travels over a path as illustrated, and is adapted to be moved ineither direction. i.e. to the left as seen in Figure 4, when the worm 21 is in engagement with the Worm wheel 23, and to the right when the worm 22 is in engagement with the worm wheel 24.

30, 30 area pair of supporting arms, fixed to and extending from one side frame 12, and carrying, at their outer free ends, three support members 31, 32 and 33.

The members 31 and 32 are identical and are mounted at either side of the member 33 b as shown in Figures 1 and 2, the member 33 acting as a spacing element separating the members 31 and 32, into which a projecting fin 20 of the ear 20 is adapted to ride.

Each of the members 31 and 32 have projecting arms 34 and 35 and a pivot 36 passes through these two arms and the ear 20 of the member 16, and forms a pivotal support for the latter.

The two members 31 and 32 are further provided with angular slots 37 and 38 which form a guideway for the travel of a loosepin 39. Formed in the fin 20 of the yoke 16 is a slot 40, shaped like an inverted V, through which the pin 39 passes. At a point 41 of the slot 40 a slight notch is located.

The outer free ends of the pin 39 carry coil springs 12 and 43 which hold the said pin continuously under tension from connections at their opposite ends with an extension 33 on the fixed member 33.

Motion is imparted to the platen 10 and its shaft 11 causing it to move always in the same direction, as indicated by the arrow A in Figures 2 and 4. Bevel gear 13 fixed to the shaft 11 and rotating therewith meshes with the bevel gear 14 attached to shaft 15, causing the latter to rotate and therewith turning the worms 21, 22. As illustrated, the views show the worm 21 in mesh with worm wheel 23 which is fixed to the ribbon shaft 25. lVorm 22 is free of any engagement, and with the parts in this position movement of the platen shaft 11 causes the ribbon to move in the direction of the full line arrow B, Figure 4. The various parts are maintained in the relative positions by the action of springs 42 and 43 exerting a pull on the floating pin 39 which in turn acts upon one face of the inverted V slot 10 in the fin 20 attached to yoke 16. The action of the pin against the wall of the inverted V slot cams the yoke supporting member 16, carrying therewith shaft 15 into the position shown in Figures 1 and 2, and causing the worm 21 to mesh with worm wheel 23.

When it is desired to reverse the direction of travel of the ribbon, pressure is exerted upon the yoke 16 at a point beyond its pivot 36 and at that end which is not in geared connection with a ribbon shaft (in the present showing toward the worm 22) causing the fin 20" to move from the position shown in full lines, Figure 3, toward that shown in dot and dash lines. As it moves to this position one. wall of the inverted V slot 40 causes the pin 39 to ride upward, guided at each side within the angular slots 37 and 38 until it reaches the point 41. As soon as the point 41 passes the pin 39, the pin is drawn back to its original position within its guides 37 and 38 but within the opposite leg of the inverted V slot, and the yoke 16 and mechanism carried therewith is moved into the position shown in dot and dash lines, Figure 3. The worm 22 will then mesh with the worm wheel 24 and motion transmitted to shaft 15 thereafter will cause the shaft 26 to turn and draw the ribbon in the direction of the dotted arrow indicated at C, which, it will be observed, is the reverse of that previously described.

The tension of the springs 42 and 43 is sufiicient to keep the pin 39 well seated in either side of the inverted V slot 10 and thereby keep the worms in positive contact with their respective worm wheels.

It will be observed that when one worm is in mesh and driving its worm wheel, the

opposite worm must be free and out of engagement, allowing the shaft which it is intended to drive to idle freely and thereby permit the ribbon to be unwound therefrom and rewound upon the driven ribbon shaft.

When it is desired to remove a ribbon entirely from the machine for replacement by a new one, the yoke 16 is moved to a neutral position half way between its two operating points, at which point the pin 39 will be brought to rest within the slight dwell at ll in the V slot 40. The yoke will then be held in a neutral position with both worms out of engagement with their respective worm wheels and both ribbon shafts will be free to turn. The ribbon can then be rapid- 1y unwound from both shafts and a new one made fast and rewound quickly by turning the worm wheels by hand. When the new ribbon is taut, the yoke is moved in either desired direction and engagement is again established between a worm and worm wheel for tne automatic feeding of the ribbon by the action of the revolving platen.

It will be evident that the rockable shaft 15 may be driven in other Ways from that shown, and that in its broader aspects my invention requires the movement of the worm gears radial with respect to the worm wheels, as by rocking the worm gear driving shaft, without regard to the means of driving of the rockable shaft.

It will also be evident that various means may be employed to cause the ribbon to move in opposite directions with reversal of the worm gear engagement. For example, I have shown the teeth of both worm gears cut in the same direction, but the ribbon wound clockwise on one spool and counterclockwise on another spool. I could equally well use one right hand and one left hand worm gear and wind both spools in the same direction.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will. doubtless become evident to others skilled in the art, to obtain part or all of the benefits of myinvention without copying the structure shown, and I, therefore, claim all such in so far as they fall within the reasonable spirit and scope of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a ribbon reverse for type impression machines in which the ribbon is driven from a platen, a rocking rotatable shaft transverse to the axis of the platen located at one end of the platen and having its axis of rocking in the platen axis of rotation, geared connection between the rocking shaft and the platen throughout its rocking movement, worms on the rocking shaft on opposite sides of its rocking pivot point, worm wheels adjacent to the WOIIIIS and adapted to be engaged alternatively by their adjacent Worms in the limiting positions of the shaft and ribbon spools, one connected to each Worm Wheel, rotatable therewith and adapted to be driven by the Worm Wheel or to idle With it.

2. In a typewriter, a platen shaft, a platen carried by the platen shaft, a platen gear at one end of the platen shaft, a yoke rockable about an axis extending longitudinally of the platen shaft, a transverse shaft carried by the yoke and rotatable therein, a gear on the transverse shaft meshing With the gear on the end of the platen shaft in all positions of the yoke, ribbon spool shafts, and Worm Wheels, one on each ribbon spool shaft, and Worms, one on each end of the transverse shaft, rotatable With it and alternately meshing with the Worm gears in opposite limiting, rocking positions of the yoke.

8. The mechanism of claim 2 characterized by stationary supporting structure and a spring detent connection between the yoke and said structure resiliently holding the yoke alternatively in either operating position and to successively resiliently retract and advance When, in order to reverse the operation of the ribbon, the yoke is angularly shifted from either operating position to the other.

PAUL PIERRE BOURQUIN. 

